[sdiy] saw to tri/sine options

[Scott Nordlund]

> ...with some pots instead of just trimmers (like the gain pot idea Mark mentioned), see what happens when you mess with the symmetry and the input level? I think Germanium transistors would be tricky but might give you an interesting sound if you can get a hold of a pair, a la a Fuzz Face or Zvex Fuzz Factory (though that might open a whole can of worms/mojo-voodoo debate when it comes to finding the 'right', if there is such a thing, beta values for the Germanium transistors). I wana give it a try on the breadboard today.



I would guess probably the most useful thing you could do would be a gain/offset adjustment on the input.  Anything more than that and you might be better off making a dedicated "tube screamer" style circuit (which is basically a symmetric bipolar logarithm).  You could add a little socket and put in LEDs, diode-connected MOSFETs, germanium, Schottky, Zener, solar cells, whatever..



> Another question though: do you get a peak-ish wave when you run a sine into the same sine waveshaper? Sin^2(x)?



It's just distorting the triangle wave a little to make the sine, so it would distort it a little more.

Instead of reducing the triangle's odd harmonics, you'd be adding them (..but with different phase compared to the original triangle).  Imagine doing it repeatedly (or with higher gain)- you'd eventually get a square.



sin^2(x) = 1/2(1-cos(2x)), basically just doubling the frequency.  You can do it with a ring modulator (...or chebyshev polynomial, if anyone wants to make a module for that).

_________________________________________________________________
Lauren found her dream laptop. Find the PC that’s right for you.
http://www.microsoft.com/windows/choosepc/?ocid=ftp_val_wl_290